Fly populations associated with landfill and composting sites used for household refuse disposal

Calyptrate fly populations were monitored with sticky traps at the following sites in Hampshire, UK during August to November 1998: a landfill and composting site (Paulsgrove), a site adjacent to this landfill (Port Solent), a site with no landfill nearby (Gosport), and a composting site with no landfill nearby. Overall, house flies Musca domestica (Linnaeus) and lesser house flies Fannia spp. were not important constituents of the dipteran catch, while bluebottles (Calliphora spp.) and greenbottles (Lucilia spp.) comprised approximately 12% of the total. Very large fly populations were found at the two composting sites, and it seems likely that these provide ideal breeding grounds for a range of fly species since they offer an abundance of warm decaying organic matter. Large fly populations were also evident at the landfill site. The suitability of household waste for the development of calyptrate Diptera was confirmed in a controlled trial: a mean of 0.43 adults emerged per kilo of one-week-old waste. Since many hundreds of tonnes of waste are delivered to the landfill daily, it is clear that the landfill is likely to substantially increase the local population of calyptrate flies. However, the data suggest that there was little movement of Diptera from the landfill to Port Solent situated approximately 500 m away. The most important calyptrate flies at this site were the cluster flies Pollenia rudis (Fabricius) and P. amentaria (Scopoli); the landfill site is unlikely to provide a suitable breeding site for these flies, as the larvae develop as parasites of earthworms. Significantly more flies emerged from oneweek-old than from two-week-old household waste. A comparison of different barriers to the emergence of adult house flies from waste demonstrated that sacking provided an effective barrier to fly emergence, but that soil did not differ significantly from control treatments. If managed appropriately, it seems that the use of sacking over landfill waste could substantially reduce associated fly populations.